1. Field of the Invention
The present invention relates to a flash photographing apparatus comprising a flash unit capable of automatically adjusting the amount of emitted light according to the brightness of the object to be photographed, and a camera for photographing said object illuminated by the flash light from said flash unit, and more particularly, to a control system for controlling the various components included in said flash unit and camera.
2. Description of the Prior Art
In the technology of flash photographing apparatus of the class described, it has been known in recent years to employ so-called TTL light-controlled flash photographing apparatus in which a light receiving element provided on a camera receives the light reflected by an object illuminated by the flash unit and terminates the light emission from the flash unit when the aggregated amount of reflected light reaches a predetermined value, thereby controlling the light available for exposure.
Such flash photographing apparatus necessitates transmission lines for transmitting information between the camera and the flash unit, and therefore there have been required additional connecting wires and terminals for the transmission of such information in addition to the conventional information transmitting channels such as for information on the state of the synchronizing switch on the camera or information on the completion of charging of the main capacitor in the flash unit. Such arrangements have inevitably resulted in complicated wiring between the flash unit and camera and also in the possibility of malfunctions arising from incomplete electrical contacts.